usr/lib/learn/editor/L8.2c

#print
You can also use "-" in addresses.
For example, you can print the
line before the current line with
  .-1p
as a command.  Again, I'll put
you in the editor; print the fifth
line and then the fourth, using this
command to print lines in reverse
order.  Then leave with w, q, and ready.
#create Ref
carrots
squash
83
#create file
broccoli
mushrooms
cauliflower
squash
carrots
lettuce
string beans
peas
lima beans
#copyout
#pipe
ed file
#user
#unpipe
#uncopyout
tail -3 .ocopy >X1
#cmp Ref X1
#log
#next
9.1a 10
9.2a 5